وَقُلْ جَآءَ ٱلْحَقُّ وَزَهَقَ ٱلْبَـٰطِلُ ۚ إِنَّ ٱلْبَـٰطِلَ كَانَ زَهُوقًا ٨١
And say, "Truth has come, and falsehood has departed. Indeed is falsehood, [by nature], ever bound to depart."
Saheeh International · QuranEnc v1.1.2
Another translation: Al-Hilali & Muhsin Khan · QuranEnc v1.1.2
81. And say: "Truth (i.e. Islâmic Monotheism or this Qur’ân or Jihâd against polytheists) has come and Bâtil (falsehood, i.e. Satan or polytheism) has vanished. Surely Bâtil is ever bound to vanish."
The verse he recited while breaking the idols; it is not itself about the conquest.